DC-to-DC converters change DC electrical power from one voltage level to another. Typically, a DC-to-DC converter converts a supply voltage level of DC power to an output voltage level. For example, 1.5 volts DC from a battery can be stepped up to a higher voltage to operate electronic circuitry. DC-to-DC converters can also provide noise isolation, power bus regulation, etc.
There are various types of DC-to-DC converters including buck converters, boost converters, buck-boost converters, and “Cuk” converters. The buck converters and the boost converters step the input voltage down and up, respectively, and buck-boost converters and Cuk converters can either step the input voltage up or down.
Different designs for DC-to-DC converters exist. Certain DC-to-DC converters have the input ground of a primary side isolated from the output ground of a secondary side, typically using an isolation transformer. Typically, isolation is provided for safety reasons and to prevent current ground loops. One drawback of isolated power supplies is that when the power supply utilizes primary side switching to produce the output voltage, feeding back the output voltage from the secondary side to the primary side to drive a controller on the primary side can be problematic.
Accordingly, it is desirable to provide a control circuit for a DC-to-DC power converter having lossless or near lossless switching and very few parts to reduce cost. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.